The modulation of immune response activity is one of the major goals in the development of novel therapeutics for auto-immune and inflammatory diseases. The innate system resides at the intersection of the pathways of microbial recognition, inflammation, and cell death, thereby offering various therapeutic targets. In this context, NOD1 and NOD2 are of particular interest, since they recognize distinct structures derived from bacterial peptidoglycans and directly activate NF-KB, a central regulator of immune response, inflammation, and apoptosis. Mutations in the NOD1 and NOD2 genes are associated with a number of human inflammatory disorders, including Crohn's disease (CD), Blau syndrome, early-onset sarcoidosis, and atopic diseases, which characteristically cause constitutive NF-:B activation. Chemical inhibitors of NOD1 and NOD2 would provide powerful research tools for elucidating the roles of these proteins in primary cultured cells from humans and in animal models. In this proposal, we describe cell-based HTS assays that utilize NF-:B-mediated luciferase reporter gene activity as a measure of NOD1 and NOD2 modulation. We also describe a secondary assay to confirm compound selectivity towards NOD activity, by measuring secretion into culture supernatants of interleukin-8 (IL-8), an endogenous NF-:B target gene. When combined with insights provided by cheminformatics analysis, and a variety of additional downstream assays provided by the assay provider for deconvoluting hits, we expect to obtain candidate compounds for subsequent optimization by medicinal chemistry. PUBLIC HEALTH RELEVANCE: [unreadable] Our goal is to identify chemicals that inhibit NF-:B activity induced by NOD1 and NOD2 proteins. The NOD1 and NOD2 proteins are members of the NLR family, a large group of host defense proteins that contain a shared architecture of Nucleotide-binding NACHT domains and pathogen-sensing LRRs. Chemical inhibitors of these innate immunity proteins will provide powerful research tools for evaluating the roles of NLR-family members in host-pathogen responses, inflammatory diseases and autoimmunity. [unreadable] [unreadable] [unreadable]